--  @testpoint:opengauss关键字called(非保留)，作为函数名
--关键字不带引号-成功
drop function if exists called;
create function called(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function called;

--关键字带双引号-成功
drop function if exists "called";
create function "called"(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/
--清理环境
drop function "called";

--关键字带单引号-合理报错
drop function if exists 'called';
create function 'called'(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/

--关键字带反引号-合理报错
drop function if exists `called`;
create function `called`(i integer)
returns integer
as $$
begin
    return i+1;
end;
$$ language plpgsql;
/